On Thu, Sep 19, 2013 at 02:51:10PM +0200, Daniel Vetter wrote: > On Thu, Sep 19, 2013 at 01:41:53PM +0100, Chris Wilson wrote: > > On Thu, Sep 19, 2013 at 02:35:42PM +0200, Daniel Vetter wrote: > > > On Thu, Sep 19, 2013 at 2:30 PM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Sep 19, 2013 at 02:06:39PM +0200, Daniel Vetter wrote: > > > >> No buffer overflows here, but better safe than sorry. > > > >> > > > >> v2: > > > >> - Fixup the sizeof conversion, I've missed the pointer deref (Jani). > > > >> - Drop the redundant GFP_ZERO, kcalloc alreads memsets (Jani). > > > >> - Use kmalloc_array for the execbuf fastpath to avoid the memset > > > >> (Chris). I've opted to leave all other conversions as-is since they > > > >> aren't in a fastpath and dealing with cleared memory instead of > > > >> random garbage is just generally nicer. > > > > > > > > I still don't agree with this change to kmalloc_array. The code is > > > > written explicitly such that an invalid buffer_count is reported as > > > > EINVAL and not ENOMEM. > > > > > > It's just paranoia - imo consistently using kcalloc/kmalloc array > > > where possible is just safer. Note also that the subtest I've added > > > explicitly checks for EINVAL, so if we ever botch this it should get > > > caught. > > > > Paranoia for what? Checking the same thing twice in case the compiler > > changes it mind? > > The compiler actually removes the 2nd check since it's the same ;-) I just > like the consisten pattern and cozy feeling that we'll have less to worry > for potential overflows. I can ditch it if you deem it too offensive. Having been along this road before, I preferred the explicit checking that also gets the right return value. The goal here is perform all sanity checks as early as possible - but I'm not going to fight to move the cliprects test as cliprects are broken by design. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
